Stove for burning combustible solid fuels

Abstract

A stove (10) for burning combustible solid fuels (64) comprising an enclosed firebox (16), a baffle (54) dividing the firebox into a lower combustion chamber (18) and an upper chamber (20) spaced from the front wall (36,46) of the firebox to permit combustion gases to flow from the combustion chamber into the upper chamber, a door (24) for facilitating introduction of solid fuel into the combustion chamber, an outlet flue (48) communicating with the upper chamber for withdrawing combustion gases from the firebox, a viewing window (38) in a wall of the firebox for enabling the fire to be viewed without opening the door of the firebox, an air inlet (72) for admitting a flow of air into the firebox and means (84) for splitting a flow of air admitted through the air inlet into first and second portions and for directing the first portion toward the bottom of the combustion chamber and the second portion into a stream of hot combustion gases passing from the combustion chamber to the upper chamber; a shroud ( 50) spaced from the back wall (60) of the firebox for preventing radiant heat transfer rearwardly of the stove and for directing a flow of fan forced air across the hot top and side walls (42,44,48) of the firebox to increase convective heat transfer and an air injection conduit (104) communicating between the space between the shroud and the back wall of the firebox and the bottom of the combustion chamber for introducing fan forced additional combustion air into the combustion chamber.

We claim: 
     
       1. A stove for burning combustible solid fuels comprising: an enclosed firebox;   baffle means for dividing said firebox into a lower combustion chamber and an upper chamber and for permitting gases from said combustion chamber to flow into said upper chamber;   means for facilitating introduction of combustible solid fuel into said combustion chamber;   outlet means communicating with said upper chamber for withdrawing combustion gases from said firebox;   air inlet means through a wall of said firebox for admitting a flow of air into the firebox;   means for splitting a flow of air admitted into said firebox through said air inlet means into first and second portions and for directing said first portion of air toward the bottom of said combustion chamber and said second portion of air toward said upper chamber;   said baffle comprising a generally horizontal portion extending from the back wall of the firebox to a point spaced from the front wall of the firebox and an upwardly projecting portion extending from said horizontal portion generally parallel to said front wall to a point spaced from the top of said firebox; and   said upwardly projecting portion and said front wall defining a passageway through which gases may pass from said combustion chamber to said upper chamber.   
     
     
       2. A stove according to claim 1, further comprising grate means in said combustion chamber for supporting solid fuel above the hearth in said combustion chamber whereby air may circulate underneath said fuel. 
     
     
       3. Apparatus according to claim 1, wherein said generally horizontal baffle portion is spaced from the side walls of said firebox, whereby a portion of the gases from said combustion chamber may pass from said combustion chamber to said upper chamber without going through said passageway. 
     
     
       4. A stove according to claim 1, wherein said firebox comprises a generally flat hearth, generally vertical combustion chamber front, back and side wall portions extending upwardly from the periphery of said hearth, a generally horizontal top wall having a substantially smaller area than said hearth, a generally vertical upper chamber back wall substantially coplanar with said combustion chamber back wall portion and receding upper chamber front and side walls extending from the tops of the respective combustion chamber front and side wall portions to said horizontal top wall. 
     
     
       5. A stove according to claim 4, wherein said upper chamber front and side walls are inclined approximately 45 degrees from vertical. 
     
     
       6. A stove according to claim 1, wherein said outlet means comprises a flue communicating with said upper chamber through the top wall thereof. 
     
     
       7. A stove according to claim 1, wherein said outlet means comprises a flue communicating with said upper chamber through the rear wall thereof. 
     
     
       8. A stove according to claim 1, further comprising damper means for regulating the flow of air through said air inlet means into the firebox. 
     
     
       9. A stove according to claim 8, further comprising hood means over said damper means. 
     
     
       10. A stove according to claim 1, wherein said air inlet means comprises a horizontally elongated opening adjacent the top of the combustion chamber front wall portion. 
     
     
       11. A stove according to claim 1, wherein said firebox comprises a single wall enclosure. 
     
     
       12. A stove according to claim 1, wherein said first portion of air is substantially larger than said second portion of air. 
     
     
       13. A stove according to claim 1, further comprising window means in the front wall of said combustion chamber. 
     
     
       14. A stove according to claim 13, wherein said window means comprise at least one of substantially transparent, heat-resistant glass for facilitating viewing of a fire in said firebox. 
     
     
       15. A stove according to claim 14, wherein said air inlet means is disposed adjacent the top of said window means. 
     
     
       16. A stove according to claim 15, wherein said splitter means directs said first portion of air downwardly across said window means, whereby soot and dirt are prevented from accumulating on the inside of said window means. 
     
     
       17. A stove according to claim 14, further comprising screen means removably positionable over the exterior of said window means. 
     
     
       18. A stove according to claim 14 further comprising grate means in said firebox adjacent said window means for preventing solid fuel in said combustion chamber from falling against said window means. 
     
     
       19. A stove according to claim 1, further comprising pedestal means for supporting said firebox in an elevated position. 
     
     
       20. A stove according to claim 9, further comprising shroud means spaced from the back wall of the firebox for inhibiting radiant heat transfer rearwardly of said stove. 
     
     
       21. A stove according to claim 20, further comprising forwardly projecting flange means along the top and side margins of said shroud means. 
     
     
       22. A stove according to claim 21, further comprising fan means for forcing a stream of air between said shroud means and the back wall of said firebox and thence over the top and side walls of said firebox. 
     
     
       23. A stove according to claim 22, wherein said fan means comprises a variable speed electric fan. 
     
     
       24. A stove according to claim 22, wherein said fan means is mounted in said pedestal means. 
     
     
       25. A stove according to claim 1, wherein said firebox is provded with a ceramic lining. 
     
     
       26. A stove according to claim 25, wherein said ceramic lining comprises a layer of firebrick at the bottom of the combustion chamber. 
     
     
       27. A stove according to claim 1, wherein said splitter means comprises a baffle adjacent said air inlet means. 
     
     
       28. A stove according to claim 27, wherein said baffle comprises a curved splitter plate having a substantially S-shaped vertical cross section. 
     
     
       29. A stove according to claim 28, wherein the lower extremity of said S-shaped splitter plate directs said first air portion downwardly across the front wall of said combustion chamber. 
     
     
       30. A stove according to claim 1, wherein said fuel introduction facilitating means comprises an openable and closeable, substantially air-tight door through a wall of the combustion chamber. 
     
     
       31. Apparatus according to claim 30, wherein said door means comprises a rotatable latch mechanism having an elongated handle which extends downwardly when said latch is in a closed and locked position, whereby the gravitational force acting upon said elongated handle urges said latch toward said closed and locked position. 
     
     
       32. A stove according to claim 30, wherein said door is formed in a side wall of the combustion chamber. 
     
     
       33. A stove for burning combustible solid fuels comprising: an enclosed firebox;   means for dividing said firebox into a lower combustion chamber and an upper chamber and for permitting gases from said combustion chamber to flow into said upper chamber;   means for facilitating introduction of combustible solid fuel into said combustion chamber;   outlet means communicating with said upper chamber for withdrawing combustion gases from said firebox;   air inlet means through a wall of said firebox for admitting a flow of air into the firebox;   means for splitting a flow of air admitted into said firebox through said air inlet means into first and second portions and for directing said first portion of air toward the bottom of said combustion chamber and said second portion of air toward said upper chamber;   pedestal means for supporting said firebox in an elevated position;   shroud means spaced from the back wall of the firebox for inhibiting radiant heat transfer rearwardly of said stove;   forwardly projecting flange means along the top and side margins of said shroud means;   fan means for forcing a stream of air between said shroud means and the back wall of said firebox and thence over the top and side walls of said firebox; and   air injection means communicating between the space between said shroud means and the back wall of said firebox and the bottom of the combustion chamber through which combustion air may be delivered to a fire burning in said combustion chamber.   
     
     
       34. A stove according to claim 33, wherein said injection means is a conduit leading from the space between said shroud and the back wall of the firebox to the bottom of the combustion chamber. 
     
     
       35. A stove according to claim 34, wherein said injection means traverses a high temperature area of said firebox, whereby air passing through said injection means may be preheated before being discharaged at the bottom of said combustion chamber. 
     
     
       36. A stove according to claim 35, wherein said injection means extends adjacent said dividing means from the back of said firebox to the front of said firebox and thence downwardly along the front wall of said combustion chamber toward the hearth. 
     
     
       37. A stove according to claim 36, further comprising deflector means for directing a stream of air discharging from said injection means toward the hearth at the bottom of said combustion chamber. 
     
     
       38. A stove according to claim 36, wherein said injection means extends through said upper chamber adjacent said baffle and thence downwardly along the front of said stove to a discharge point adjacent the hearth. 
     
     
       39. A stove for burning combustible solid fuels comprising: an enclosed firebox;   means for dividing said firebox into a lower combustion chamber and an upper chamber and for permitting gases from said combustion chamber to flow into said upper chamber;   means for facilitating introduction of combustible solid fuel into said combustion chamber;   outlet means communicating with said upper chamber for withdrawing combustion gases from said firebox;   air inlet means through a wall of said firebox for admitting a flow of air into the firebox;   means for splitting a flow of air admitted into said firebox through said air inlet means into first and second portions and for directing said first portion of air toward the bottom of said combustion chamber and said second portion of air toward said upper chamber;   said splitting means comprising a baffle adjacent said air inlet means;   said baffle comprising a curved splitter plate having a substantially S-shaped vertical cross section, and the outer surface of the upper curve of said S-shaped splitter plate forming a restricted venturi throat with the front wall of said combustion chamber above said air inlet means.   
     
     
       40. A stove for burning combustible solid fuels comprising: an enclosed firebox;   means for dividing said firebox into a lower combustion chamber and an upper chamber and for permitting gases from said combustion chamber to flow into said upper chamber;   means for facilitating introduction of combustible solid fuel into said combustion chamber;   outlet means communicating with said upper chamber for withdrawing combustion gases from said firebox;   air inlet means through a wall of said firebox for admitting a flow of air into the firebox;   means for splitting a flow of air admitted into said firebox through said air inlet means into first and second portions and for directing said first portion of air toward the bottom of said combustion chamber and said second portion of air toward said upper chamber;   said splitting means comprising a baffle adjacent said air inlet means;   said baffle comprises a curved splitter plate having a substantially S-shaped vertical cross section, the upper extremity of said S-shaped splitter plate partially closing off the space between the front wall of the combustion chamber and the dividing means whereby the cross sectional area of the opening from the combustion chamber to the passageway between the upwardly projecting portion of said dividing means and the front wall of said upper chamber is less than the cross sectional area of said passageway.